1. Field of the Invention
The present invention relates generally to a bobbin hanger of the type which is in general use mostly for feeding spinning machines with rovings. Its construction must be such that the bobbin may be held by the bobbin hanger when it is simply thrust up onto the bobbin hanger, thus applying it thereto, or that the bobbin may be released when thrust up once more, thus to be removed therefrom. Consequently, it is desirable that they both be constructed to rotate freely and uniformly and further to be able to stand long term use. The present invention has been contrived with the object of satisfying these requirements, wherein the bearing section holding the bobbin hanger is so constructed as to be rotated readily and to continue the rotation constantly and uniformly, as a result of deterring the entrance of dust thereinto.
2. Description of the Prior Art
The conventional bobbin hanger used chiefly for spinning machines and mechanical appliances dealing with bobbins has the capability of securing and releasing such bobbins without difficulty. In many cases involved, the barrel body of the bobbin hanger is inserted into a bobbin-supporting hole, which is provided in the upper part of the bobbin, and then supports the bobbin at a shoulder lying between the bobbin-supporting hole and a large diametral hollow part extended at the depths thereof through the medium of two or more fingers or arms projecting in plural directions from the lower part of the barrel body. This kind of bobbin hanger is well known, for example, in the U.S. Pat. Nos. 2,943,812, 2,876,962, 3,065,926 and 3,286,949.
Now, the practicability of easily loading and unloading the bobbin is of course a fine thing, but it is also important that the suspended bobbin may be rotated smoothly and uniformly. Accordingly, almost all bobbin hangers proposed so far have made use of ball bearings, being hung on creel board or creel rail of spinning machines, and being used by the hundreds of thousands, whereby they are required to be offered at light weight and low cost as much as possible. That is why metal material is used only in the principal part of their ball bearing section and the remaining part is made up of synthetic resinous material of good abrasion resistance. The ball bearing thus constructed is supported by a shank penetrating therethrough. Since the ball bearing section, however, is required to rotate and swing with freedom, there must be an adequate clearance between it and the shank. If this clearance is more narrow than necessary, it becomes impossible for the ball bearing section to swing, even though allowed to rotate. It is the problem of this clearance that always perplexes the designer of the ball bearing section. That is to say, there is the possibility of the ingress of dust, such as fly, flint, sand and the like from this clearance in the spinning room where they are suspended in the air in a great measure, therefore either leading to the disturbance of its smooth rotation, which compels the same to be overhauled, or resulting in the impossibility of feeding rovings, so far as spare parts not replaced.
Hereupon, a very careful countermeasure should be taken in order to prevent the intrusion of dust. In the environment of the spinning room, there are intermingled other than fly, etc., dust or powders of sand, iron, magnesium, aluminum and so on. These fine powders often abrade the bearing race of the ball bearing so that the years of endurance of the bobbin hanger are shortened and the durability of the ball bearing section is lowered. Considering these circumstances, hitherto there has been proposed a bobbin hanger of such a kind having a cap for the prevention of dust in the clearance of the ball bearing section, but it has been of a fixed type and rather placed the swing of the supporting barrel body under restraint.